With 800,000 people expected to be looking on, Monday's swearing-in ceremony will be one of the most-watched events of the year. So who are the lucky folks that get to flank President Obama and Vice President Biden on stage? Here's your cheat sheet.

The United States Marine Band

The U.S. Marine Band plays at an Independence Day barbeque for members of the military and their families on the South Lawn of the White House in Washington July 4, 2011.

Known as “The President’s Own,” this Marine Corps band’s primary mission is to provide music for the president. On Monday, they’ll be first up in the program, tasked with playing the opening music and prelude to the ceremonial swearing-in. The band has had a front row seat to history since 1798, when it was founded by an act of Congress; hence, it is the the nation’s oldest continuously active professional music organization. All the musicians are members of the U.S. Marine Corps and perform regularly at White House events and at more than 500 public appearances every year, including state funerals, state arrival ceremonies and Washington’s Friday evening parades in the summer. The band has played at every presidential inauguration since 1801, when Thomas Jefferson was sworn in.